Initial justification through Baptism is a rebirth, or a second birth. There's a broader sense for justification apart from this justification discussed in Trent that is a natural justification rather than a supernatural one.
Supernatural life is on top of the natural life, and one can be naturally right with God without having been elevated to the supernatural life, which is a free gift of God and not owed to nature.
If God had created Adam and Eve without any intention to elevate them to the supernatural state, they would still have been in a state of justice before their fall, but it would have been a natural, rather than a supernatural, justice.
"Adoption as the sons of God" refers specifically to being adopted into the inner life of God, i.e. as adopted to within the life of the Holy Trinity, the supernatural life.
You guys read and put stuff in bold but lack understanding.